Bonucci was a City target in the summer of course, and the Blues will re-double their efforts to sign the six ft three ins stopper when the summer transfer window opens.

But after a season in which City's defence has been a clear weak point, that shut-out – over two legs, of course – of Messi, Neymar and Suarez, was a reminder of exactly why Pep Guardiola was keen.

It was pinpointed as a weakness last summer, but attempts to sign Aymeric Laporte and Bonucci both fell through, and with Vincent Kompany struggling, Aleks Kolarov was converted into a centre back – an experiment which worked for a while.

Bonucci has been brilliant over two games against Barcelona

John Stones has all the raw materials to be a top Guardiola-style defender, and Kompany is superb when fit, but Aleks Kolarov and Nicolas Otamendi are too inconsistent to be long-term solutions.

Unless Kompany can defy the odds or Tosin Adarabioyo sort out his future, it means that Stones is the only centre back City can count on for the coming years.

The comparisons with Barcelona's Gerard Pique are relevant – both are talented young footballing defenders who need schooling in the darker arts of defending.

Pique found Carles Puyol as a tutor and template at Barca, and Bonucci would be just the man to fashion Stones.

Puyol and Pique were a strange mix – one was a fresh-faced posh boy who adorns magazine front covers, the other was a tough farm boy who spent his youth sliding around on gravel pitches.